• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.161-170
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• 2020

There is systematic spatial variations in environmental properties due to sensitive reaction to external conditions at plastic greenhouse occupied 99.2% of domestic agricultural facilities. In order to construct 3 dimensional distribution of temperature, relative humidity, CO₂ and illuminance, measurement matrix as 3 by 3 by 5 in direction of width, height and length, respectively, dividing indoor space of greenhouse was designed and tested at experimental site. Linear regression analysis was conducted to evaluate optimal estimation method in terms with horizontal and vertical variations. Even though sole measurement point for temperature and relative humidity could be feasible to assess indoor condition, multiple measurement matrix is inevitably required to improve spatial precision at certain time domain such as period of sunrise and sunset. In case with CO₂, multiple measurement matrix could not successfully improve the spatial predictability during a whole experimental period. In case with illuminance, prediction performance was getting smaller after a time period of sunrise due to systematic interference such as indoor structure. Thus, multiple sensing methodology was proposed in direction of length at higher height than growing bed, which could compensate estimation error in spatial domain. Appropriate measurement matrix could be constructed considering the transition of stability in indoor environmental properties due to external variations. As a result, optimal measurement matrix should be carefully designed considering flexibility of construction relevant with the type of property, indoor structure, the purpose of crop and the period of growth. For an instance, partial cooling and heating system to save a consumption of energy supplement could be successfully accomplished by the deployment of multiple measurement matrix.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1314-1321
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• 2006

The objective of this work was to study the effect of mixed culture solid substrate fermentation of C. tropicalis ZD-3 with A. niger ZD-8 on detoxification of cottonseed meal (CSM), and to investigate the effect of fermentation period, proportion of CSM in substrate, sodium carbonate, minerals and heat treatment on the reduction of free gossypol levels during mixed culture solid substrate fermentation of CSM. Experiment 1: Three groups of disinfected CSM substrate were incubated for 48 h after inoculation with either of the fungi C. tropicalis ZD-3, A. niger ZD-8 or mixed culture (C. tropicalis ZD-3 with A. niger ZD-8). One non-inoculated group was used as the control. Levels of initial and final free gossypol (FG), CP and in vitro CP digestibility were assayed. The results indicated that mixed culture fermentation was far more effective than single strain fermentation, which not only had higher detoxification rate, but also had higher CP content and in vitro digestibility. Experiment 2: CSM substrates were treated according to experimental variables including fermentation period, proportion of CSM in substrate, sodium carbonate, minerals and heat treatment, Then, the treated CSM substrates were inoculated with mixed culture (C. tropicalis ZD-3 with A. niger ZD-8) and incubated at $30^{\circ}C$ for 36 h in a 95% relative humidity chamber. After fermentation ended, FG and CP content of fermented CSM substrate was assayed. The results showed that the appropriate fermentation period was 36 h, and the optimal proportion of CSM in substrate was 70%. Addition of sodium carbonate to CSM substrate was beneficial for fermentative detoxification. Heat treatment could facilitate fermentative detoxification, and supplementation with minerals was instrumental in reducing gossypol levels during mixed culture solid substrate fermentation of CSM.

• Journal of Animal Science and Technology
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• v.59 no.6
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• pp.15.1-15.5
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• 2017

Background: The horse intestinal tract is sensitive and contains a highly complex microbial population. A shift in the microbial population can lead to various issues such as inflammation and colic. The use of nutraceuticals in the equine industry is on the rise and curcumin is thought to possess antimicrobial properties that may help to minimize the proliferation of opportunistic bacteria. Methods: Four cecally-cannulated horses were utilized to determine the optimal dose of liposomal-curcumin (LIPC) on reducing Streptococcus bovis/equinus complex (SBEC), Escherichia coli K-12, Escherichia coli general, Clostridium difficile, and Clostridium perfringens in the equine hindgut without adversely affecting cecal characteristics. In the first study cecal fluid was collected from each horse and composited for an in vitro, 24 h batch culture to examine LIPC at four different dosages (15, 20, 25, and 30 g) in a completely randomized design. A subsequent in vivo $4{\times}4$ Latin square design study was conducted to evaluate no LIPC (control, CON) or LIPC dosed at 15, 25, and 35 g per day (dosages determined from in vitro results) for 9 days on the efficacy of LIPC on selected bacterial strains, pH, and volatile fatty acids. Each period was 14 days with 9 d for acclimation and 5 d withdrawal period. Results: In the in vitro study dosage had no effect ($P{\geq}0.42$) on Clostridium strains, but as the dose increased SBEC concentrations increased (P = 0.001). Concentrations of the E. coli strain varied with dose. In vivo, LIPC's antimicrobial properties, at 15 g, significantly decreased (P = 0.02) SBEC when compared to 25 and 35 g dosages. C. perfringens decreased linearly (P = 0.03) as LIPC dose increased. Butyrate decreased linearly (P = 0.01) as LIPC dose increased. Conclusion: Further studies should be conducted with a longer dosing period to examine the antimicrobial properties of curcumin without adversely affecting cecal characteristics.

• Journal of the Korean Society of Food Culture
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• v.32 no.3
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• pp.227-234
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• 2017

This study attempted to establish the optimal conditions for storage of spring kimchi cabbage to stably control supply and demand. To this end, this study stored kimchi cabbages in various manners for different periods and compared the quality characteristics of kimchi using these cabbages. According to the results, pre-drying with photocatalytic and pre-cooling treatments showed average selectivity loss rates of 18.83 and 21.37%, respectively, which were lower than those of other treatments. Spring kimchi cabbages were stored for 15 weeks under various conditions, and the kimchi was stored for 4 weeks at $4^{\circ}C$. After ripening, each kimchi was analyzed for their soluble solid content, pH, acidity, and salinity. The average pH of kimchi was 4.60 and tended to rise, whereas average acidity was 0.38% and fell by 0.24 to 0.31% as the storage period was extended. Extension of the storage period caused decreases in soluble solid content and salinity, and the number of lactic acid bacteria decreased due to increased pH and reduced acidity (p<0.05). Sensory evaluation showed that all experts and non-professionals preferred kimchi treated by precooling compared to any other treatment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6C
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• pp.483-491
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• 2012

In vehicle-to-vehicle (V2V) communications, each vehicle should periodically disseminate a beacon message including the kinematics information, such as position, speed, steering, etc., so that a neighbor vehicle can better perceive and predict the movement of the vehicle. However, a simple broadcasting of such messages may lead to a low reception probability as well as an excessive delay. In this paper, we attempt to analyze the impact of the following key parameters of the beacon dissemination on the performance of vehicular networks: beacon period, carrier-sensing range, and contention window (CW) size. We first derive a beacon period which is inversely proportional to the vehicle speed. Next, we mathematically formulate the maximum beacon load to demonstrate the necessity of the transmit power control. We finally present an approximate closed-form solution of the optimal CW size that leads to the maximum throughput of beacon messages in vehicular networks.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.3
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• pp.304-312
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• 2017

This study was carried out to evaluate the effects of yam powder addition (0~40%) on the quality characteristics and oxidative stability of yackwa made with rice flour. While most rice flour (34.35%) had a particle size more than $250{\mu}m$, 75% of yam powder had a particle size less than $65{\mu}m$. Width, height, and volume of rice yackwa added with yam powder increased with increasing yam powder content. While L and b values of rice yackwa added with yam powder decreased with increasing yam powder content, a value increased. Hardness and chewiness of rice yackwa added with yam powder increased as storage period increased at $25^{\circ}C$ for 9 days, whereas they decreased with increasing yam powder content. In a discrimination test, brown color, flavor, sweetness, and bitterness increased with increasing yam powder content, whereas hardness decreased. In a preference test, taste, texture, and overall acceptance increased with increasing yam powder content. The acid and thiobarbituric acid (TBA) values of rice yackwa added with yam powder increased as storage period increased. However, acid and TBA values of the treated groups decreased with increasing yam powder content compared to the control group. Although 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activities decreased with increasing storage period, values increased with increasing yam powder content. It was found that yackwa quality, preference, and oxidative stability increased during storage with increasing yam powder content. From these results, addition of 40% yam powder would be the optimal conditions for making rice yackwa.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.51-51
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• 2023

Global warming has significant effects on the growth and development of wheat and can cause a reduction in grain yield and quality. Grain quality is a major factor determining the end-use quality of flour and a reduction in quality can result economic losses. Therefore, it is necessary to study the physiological characteristic of wheat to understand its response to temperature elevation, which can aid in the development of strategies to mitigate the negative effects of high temperature and sustain wheat production. This study investigated the effects of elevated temperature on grain characteristics and quality during the grain filling period of two Korean bread wheat cultivars Baekkang and Jokyoung. These two bread wheat cultivars were subjected to an increasing temperature conditions regime; T0 (control), T1 (T0+1℃), T2 (T0+2℃) and T3 (T0+3℃). The results showed that high temperature, particularly in T3 condition, caused a significant decrease in the number of grains per spike and grain yield compared to the T0 condition. The physical properties, such as grain weight and hardness, as well as chemical properties, such as starch, protein, gluten content and SDSS, which affect the quality of wheat, were changed by high temperature during the grain filling period. The grain weight and hardness increased, while the grain size not affected by high temperature. On the other hand, amylose content decreased, whereas protein, gluten content and SDSS increased in T3 condition. In this study, high temperature within 3℃ of the optimal growth temperature of wheat, quantity properties decreased while quality-related prosperities increased. To better understand the how this affects the grain's morphology and quality, further molecular and physiological studies are necessary.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.358-365
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• 2015

ε-Poly-L-lysine (ε-PL) is a homopolymer of L-lysine molecules connected between the epsilon amino and alpha carboxyl groups. This polymer is currently used as a natural preservative in food. Insufficient biomass is a major problem in ε-PL fermentation. Here, to improve cell growth and ε-PL productivity, various nitrogen-rich nutrients were supplemented into flask cultures after 16 h cultivation, marking the onset of ε-PL biosynthesis. Yeast extract, soybean powder, corn powder, and beef extract significantly improved cell growth. In terms of ε-PL productivity, yeast extract at 0.5% (w/v) gave the maximum yield (2.24 g/l), 115.4% higher than the control (1.04 g/l), followed by soybean powder (1.86 g/l) at 1% (w/v) and corn powder (1.72 g/l) at 1% (w/v). However, supplementation with beef extract inhibited ε-PL production. The optimal time for supplementation for all nutrients examined was at 16 h cultivation. The kinetics of yeast-extract-supplemented cultures showed enhanced cell growth and production duration. Thus, the most commonly used two-stage pH control fed-batch fermentation method was modified by omitting the pH 5.0-controlled period, and coupling the procedure with nutrient feeding in the pH 3.9-controlled phase. Using this process, by continuously feeding 0.5 g/h of yeast extract, soybean powder, or corn powder into cultures in a 30 L fermenter, the final ε-PL titer reached 28.2 g/l, 23.7 g/l, and 21.4 g/l, respectively, 91.8%, 61.2%, and 45.6% higher than that of the control (14.7 g/l). This describes a promising option for the mass production of ε-PL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.822-831
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• 2000

Application of omija(Schizndra chinensis Baillon) to improve the quality and preservation of nabka kimchi was attempted and the optimal amount of omija level and its effect on the sensory and microbiological properties of nab마 kimchi during fermentation were examined. Effects of omija juice which had been prepared by extracting omija seeds for 9 hr at room temperature (22.5$\pm$0.5$^{\circ}C$) with different ratios (0.5, 1.0, 1.5, 2.0%;w/v) of water were examined against control (kimchi prepared without omija). Organoleptic and microbiological properties of nabak kimchi were measured up to 25 days at 1$0^{\circ}C$ after preparation. Sensory properties were evaluated in the aspects of both acceptability and intensity characteristics. In whole, 0.5 and 1.0% treatments showed higher values of evaluation, compared to control, 1.5, and 2.0% treatments throughout the fermentation period. As fermentation progresses, however, sample of 1.0% treatment ranked first between day 4 to 7 and also so did sample of 0.5% treatment along with 1.0% treatment from behind day 10. As for color, control, 0.5% treatment, and 1.0% treatment were more favored than rest of the samples. In texture, 2.0% treatment showed the highest values, whereas control was rated the lowest. In the intensity of characteristics 1.5% and 2.0% treatments showed higher values except sweet taste in which 1.0% treatment ranked top during the initial 7 days and then 0.5% treatment took the first place at behind day 10. total cell counts and number of lactic acid bacteria were gradually increased and then decreased showing the maximum levels of microbial counts on different days, to say, day 2 for control and 0.5% treatment nd day 7 for 1.0, 1.5 and 2.0% treatments. The application of omija juice in nabak kimchi enhanced eating qualities of the fermented product and the fermentation-retarding effect of omija juice was clearly shown during the initial seven days of fermentation. The optimum levels of omija juice in nabak kimchi obtained through experiments were between 0.5 to 1.0% for color, fermentation-retarding effects, and savory taste of the product.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.338-345
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• 2001

An experiment was conducted to determine the optimal inclusion ratio of spray dried plasma protein (SDPP) and dried porcine solubles (DPS) for maximizing growth and improving immunity in weaned pigs. One hundred-fifty male (barrow) pigs were allotted in a completely randomized block design. Treatments were as follows: 1) control (6% SDPP), 2) S6D6 (6% SDPP+6% DPS), 3) S6D3 (6% SDPP+3% DPS), 4) S3D6 (3% SDPP+6% DPS) and 5) S3D3 (3% SDPP+3% DPS). Each treatment has 6 replicates with 5 pigs per replicate. Average daily gain (ADG) and average daily feed intake (ADFI) were highest, but not significantly different when pigs were fed a diet contained 6% SDPP and DPS from d 0 to 7 after weaning. Pigs fed the S6D3 diet showed better weight gain and feed intake than other treatments, especially compared with pigs fed S3D6 diet (p<0.05) from d 8 to 21 after weaning. For the overall experimental period, pigs fed the S6D3 diet showed the best improvement in ADG and ADFI. The digestibilities of dry matter (DM) and crude protein (CP) were higher in pigs fed the S6D6 diet than other diets from d 0 to 7 after weaning. However, pigs fed S6D3 diet showed higher DM, CP and essential amino acids (except methionine and arginine) digestibilities than pigs fed other diets from d 8 to 21 after weaning, although there was no significant difference. From d 8 to 21 after weaning, threonine, valine, isoleucine and leucine digestibilites were higher in S6D6 group, and phenyalanine, histidine, lysine and arginine digestibility were higher in S6D3 group than other groups. The ratio of CD4 and CD8 positive lymphocytes during the overall experimental period was independent of the ratio of SDPP and DPS. However, CD4+:CD8+ ratio was numerically lowered in pigs fed diet the S6D3 diet. Therefore, the present study suggests that an optimal inclusion ratio for maximizing growth performance and maintaining low immune status is 6% of SDPP and 3% of DPS in weaned pigs.